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Tests disc brake potentiometer readings.

PotentiometerTester

Tests wear status of brake pads and discs.

Part No: DRA01

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Operation of the tester

1. Connect the appropriate test cable or adaptor to the tester via the phono connector at the top of the device.

2. Connect the cable to the potentiometer being tested.3. Turn on the tester, press select button to scroll through vehicle/potenti-

ometer choices.4. Press and hold select button to choose potentiometer5. If no potentiometer is connected a failure message will appear .6. (failure please attach potentiometer) this means either no potentiometer

is connected or a faulty one is connected.7. Observe pad wear % and voltages from potentiometer being tested and

adjust to suit your requirements by turning the potentiometer.

Battery Before operation of the tester the battery should be fully charged, battery percentage can be seen on the display (battery supplied inside). If the bat-tery is not fully charged the accuracy of the tests cannot be guaranteed as

the tester supplies voltage to the potentiometer being tested.

Test Cable Connection

Oled Display

Battery Charge / Status Led.

On/ Off/ selection

Micro USB Battery

Selection screenSCANIA, IVECO, OTHERS3WS. (continuous )

MAN

Mercedes

Description of potentiometer tester DRA01

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SelectionVehicle manufacturer

Potentiometer Pin coating type

Information if functionIs correct

Scania iveco Mercedes 3WScontinuouscontinuos

DAFDAIMLERDANAEVOBUSHENDRIKSONHYUNDAIIVECOMERITORSAFSCANIAOTHERS

Silver

Voltage values increase be-tween maximum and minimum gap from 1 volt to 3.5 volt line-arly.

MAN Mercedes3WG continuous

MANDANALAFSAFOTHERS

Gold

Voltage values increase be-tween maximum and minimum gap from 0.7 volt to 3.56 volt linearly.

Daf Mercedes black/white 2W

DAFERFDAIMLERZFMAN

Silver

Voltage switch-es from approx 0.1volt to approx 5 volt when the minimum gap is reached.

Abbreviations

3WS, three wire silver pin potentiometer,3WG, three wire gold pin potentiometer

2W, two wire potentiometer, (also silver pin)

Screen Selection depending on vehicle and axle manufacturer

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Reference tables for 3WS potentiometer

Scania, iveco Mercedes others

Reference tables for 3WS potentiometerScania, Iveco Mercedes others

Setting the 3WS (three wire silver potentiometer)

Fully retract the tappets in the calliper with the adjuster .

Remove old housing from the calliper, insert new potentiometer into housing, make sure the two locating clips are located correctly,

Connect test cable and turn on tester, turn the spline in the centre of the potentiometer clockwise until the voltage is 1.00 volts and the pad wear is 0%, refit the housing to the calliper, refit the pads to the calliper and adjust the tappets to take up any slack, if new pads are fitted the reading should now be 0% pad wear on your vehicle display.

Brake Type

Maximum disc and

brake pad gap (mm)

Measured voltage

(V)

Minimum disc and

brake pad gap (mm)

Measured voltage (V)

Change of gap per full rotation of the adjuster*

(mm/v)

SB5 / SN5 96 1.00 66 3.50 6/0.50

SB6 / SN6 105 1.00 68 3.50 6/0.41

SB7 / SN7 105 1.00 68 3.50 6/0.41

SL7 / SM7 110 1.00 73 3.50 6/0.41

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Reference tables for 3WG potentiometerMAN, Mercedes

Setting the 3WG (three wire gold potentiometer)

Fully retract the tappets in the calliper with the adjuster

Remove old housing from the calliper, insert new potentiometer into housing, make sure the two locating clips are located correctly,

Connect test cable and turn on tester, turn the spline in the centre of the potentiometer clockwise until the voltage is 0.70 volts and the pad wear is 0%, refit the housing to the calliper, refit the pads to the calliper and adjust the tappets to take up any slack, if new pads are fitted the reading should now be 0% pad wear on your vehicle display.

Brake Type

Maximum disc and

brake pad gap (mm)

Measured voltage

(V)

Minimum disc and

brake pad gap (mm)

Measured voltage (V)

Change of gap per full rotation of the adjuster*

(mm/v)

SN5 96 0.70 66 3.56 6/0.57

SB6 / SN6 105 0.70 70 3.56 6/0.49

SB7 / SN7 105 0.70 70 3.56 6/0.49

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Reference tables for 2W potentiometerDAF, Mercedes

Setting the 2W (two wire silver potentiometer)

Wind the tappets out until there is a 66mm 0r 68mm gap from the tappet to the edge of the calliper (66mm or 68mm depends on the calliper you are using)

Remove old housing from the calliper, insert new potentiometer into housing, make sure the two locating clips are located correctly.

Connect test cable and turn on tester, turn the spline in the centre of the potentiometer anti clockwise until the voltage changes from 0.10volts to 5.00volts,at this point the tester will say fail, this is because you are setting the failure point of the pad wear (100% pad wear).

Refit the housing to the calliper then wind the tappets all the way back with the adjuster, when the pads wear to the maximum 66mm or 68mm gap the voltage will go to 5.00 volts.If new pads are fitted the reading should be 0% pad wear on your vehicle display.

Brake TypeMaximum disc and brake pad

gap (mm)

Measured voltage (V)

Minimum disc and brake pad

gap (mm)

Measured voltage (V)

SB5/ SN5 96 ≤ 0,15 66 5,00

SB6 / SN6 105 ≤ 0,15 68 5,00

SB7 / SN7 105 ≤ 0,15 68 5,00

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3WS PotentiometerScania, Iveco, Mercedes, Others.

When setting a new 3WS potentiometerThe voltage should be at 1.00 volts (approx)And the pad wear should be 0%, Status = Pass

Pot Voltage

Battery Level

Pad Wear

Pass/ fail, lowPad wear bar

Plus/minus

When the pads reach (approx) 75% worn the low pads warning will Appear, this is the point the light on the vehicle dash will come on.

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3WG potentiometerMAN, Mercedes

When setting a new 3WG potentiometerThe voltage should be at 0.70 volts (approx)And the pad wear should be 0%,Status = Pass

Pot Voltage

Battery Level

Pad Wear

Pass/ fail, lowPad wear bar

Plus/minus

When the pads reach (approx) 75% worn the low pads warning will Appear, this is the point the light on the vehicle dash will come on.

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2W potentiometerDaf, Mercedes

When setting a new 2W potentiometerThe voltage should read 5.00 volts and the pad wear should be 100% with the tappets wound out to the relevant distance.The bar graph should say fail, this is because you are setting the failure point of the pad wear.

Pot Voltage

Battery Level

Pad Wear

Pass/ fail, lowPad wear bar

When the pads reach 100% worn the fail warning will Appear, this is the point the light on the vehicle dash will come on.

Once you have set the potentiometer to the 100% pad wear.

Then wind the tappets all the way back, as you do this the pad wear will

Change to 0.10 volts and the pass warning will appear

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FREQUENTLY ASKED QUESTIONS

Q. The tester will not turn on, A. make sure the batteries are charged

Q. Display says attach potentiometer, A. If you have a potentiometer connected then its probably faulty

Q. Pad wear values keep jumping up and down randomly,A. Potentiometer faulty

Q. How do i know what potentiometer I’m testing,A. Refer to table on page 3, if still unsure try all three types on the Display until one works

Q. The tester keeps turning off,A. The tester will turn off after 1 minute

Q. I’ve lost or broken the connecting cable, can I buy anotherA. Yes contact your supplier

Q. Can I test the Maxx 22T sensorsA, Yes use the 3WG settings

Drakefield ltdUnit 60 Horndon Industrial ParkWest Horndon EssexCM13 3XL

Phone, 01277 814060Email, sales@drakefield.com

Warning advice

The potentiometer tester DRA01 is an electronic measuring device, which must be protected against excessive humidity and heat. The tester must only be connected to brakes which are supplied with a Knorr-Bremse ‘continuous’ or a ‘black/white’ sensor (potentiome-ter). The tester supplies voltage to the potentiometer being measured and therefore it must only be connected where there is no voltage, either external or from the vehicle. Usage contrary to this specification may damage the device. Warranty claims will not be honoured if the device has been opened or tampered with an any way.